Generator

ABSTRACT

A generator includes a liquid tank, a high temperature device and a nozzle unit. The liquid tank has a receiving room. The high temperature device is disposed on a surface of the liquid tank. The nozzle unit includes a tank, an injecting tube, a nozzle and an oscillating device. The tank is disposed in the receiving room and filled with a working fluid. The injecting tube has one end communicating with the tank. The nozzle is disposed on a surface of the tank and faces the high temperature device. The oscillating device is disposed on the tank to induce oscillation of the working fluid in the tank, wherein the oscillation changes the pressure of the working fluid so that the working fluid is pulled towards the nozzle and is sprayed on the high temperature device by the nozzle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a generator and, moreparticularly, to a generator that is installed in an absorptionrefrigeration system and has an improved refrigerant vaporizationefficiency.

2. Description of the Related Art

Referring to FIG. 1, a conventional absorption refrigeration system 9generally includes a generator 91, a condenser 92, an evaporator 93 andan absorber 94. The generator 91, condenser 92, evaporator 93 andabsorber 94 are connected via a plurality of circulation tubes 95 toform an enclosed loop.

The generator 91 includes a liquid tank 911 and a heat source 912. Theliquid tank 911 is filled with a working fluid. The heat source 912 canprovide heat to the liquid tank 911 to vaporize an absorbent flowing inthe working fluid. Substantially, the heat source 912 can provide heatto the liquid tank 911 in two manners: direct and indirect manners. Inthe direct manner, the heat source 912 directly heats up the generator91 using natural gas or burning oil. In the indirect manner, the heatsource 912 heats up a medium first and the medium then passes the heatto the generator 91.

The commonly available working fluid is a binary solution of ammoniawater or lithium bromide. Circulating cooling effect may be achieved viainteraction between two substances of the binary solution. Specifically,the ammonia water is a mixture of ammonia and water, with the ammoniabeing a refrigerant and the water being an absorbent. The ammonia waterhas a cooling temperature about minus 20 degree and is often used in alarge-sized refrigerator. The lithium bromide solution is a mixture oflithium bromide and water, with the water being a refrigerant and thelithium bromide being an absorbent. The lithium bromide solution has acooling temperature about 18 degree and is thus often used in anair-conditioning system. In the following description, the lithiumbromide solution is exemplarily used as the working liquid to describethe operation of the conventional absorption refrigeration system 9.

As described above, the heat source 912 provides heat to the liquid tank911 of the generator 91 to heat up the lithium bromide solution in theliquid tank 911, producing steam with high temperature and highpressure. The high-temperature and high-pressure steam enters thecondenser 92 via a first circulation tube 951 and then condenses intomiddle-temperature water which, in turn, enters the evaporator 93 via asecond circulation tube 952 and then condenses into low-temperaturewater. An expansion valve 931 is provided to reduce the pressure of thelow-temperature water and to spray the low-temperature water into athird circulation tube 953, so as to produce steam with low temperatureand low pressure. Since the absorber 94 is in a low pressure of vacuumor nearly vacuum, the low-temperature and low-pressure steam will beautomatically pulled into the absorber 94 via the third circulation tube953. Since the vaporization of liquid requires absorption of heat, thelow-temperature and low-pressure steam will absorb the heat from theambient environment for cooling effect.

The low-temperature and low-pressure steam in the third circulation tube953 will mix with the lithium bromide solution in the absorber 94 andthus dilute the lithium bromide solution. The diluted lithium bromidesolution flows to the generator 91 via a fourth circulation tube 954 sothat it can be reheated and vaporized. During vaporization of thediluted lithium bromide solution, the water contained in the dilutedlithium bromide solution will be steamed out so that the concentrationof the diluted lithium bromide solution is increased (highconcentration). The vaporized lithium bromide solution (with higherconcentration) then flows back to the absorber 94 via a fifthcirculation tube 955, causing the high-concentration lithium bromidesolution and low-concentration lithium bromide solution (the dilutedlithium bromide solution not vaporized) to constantly circulate aroundthe generator 91 and absorber 94. In addition, the conventionalabsorption refrigeration system 9 may further include a refrigeratingdevice 96 with refrigerating water flowing therein. The refrigeratingdevice 96 passes through the absorber 94 and condenser 92, limiting theliquid in the absorber 94 and condenser 92 at a predeterminedtemperature. Thus, cooling effect of the conventional absorptionrefrigeration system 9 is maintained.

Based on the above description, it can be known that the conventionalabsorption refrigeration system 9 operates on the absorbed heat of thegenerator 91, and the circulating cooling efficiency of the conventionalabsorption refrigeration system 9 is proportional to the vaporizationefficiency of the lithium bromide solution in the generator 91. However,since the conventional absorption refrigeration system 9 produces steamby heating the lithium bromide solution in the generator 91, the lithiumbromide solution is not vaporized in an efficient manner. To efficientlyvaporize the lithium bromide solution, more energy should be given tothe heat source 912 to maintain the heat source 912 at a hightemperature. However, this will consume more energy.

SUMMARY OF THE INVENTION

It is therefore the primary objective of this invention to provide agenerator with an improved refrigerant vaporization efficiency toachieve a better circulating cooling efficiency for an absorptionrefrigeration system.

The invention discloses a generator including a liquid tank, a hightemperature device and a nozzle unit. The liquid tank has a receivingroom. The high temperature device is disposed on a surface of the liquidtank. The nozzle unit includes a tank, an injecting tube, a nozzle andan oscillating device. The tank is disposed in the receiving room andfilled with a working fluid. The injecting tube has one endcommunicating with the tank. The nozzle is disposed on a surface of thetank and faces the high temperature device. The oscillating device isdisposed on the tank to induce oscillation of the working fluid in thetank, wherein the oscillation changes the pressure of the working fluidso that the working fluid is pulled towards the nozzle and is sprayed onthe high temperature device by the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 shows a diagram of a conventional absorption refrigerationsystem.

FIG. 2 shows a diagram of a generator according to a preferredembodiment of the invention.

FIG. 3 shows an exemplary application of the generator of the inventionin an absorption refrigeration system.

FIG. 4 shows a diagram of a motor cooling system of an electric vehicle.

FIG. 5 shows a coupling diagram of the generator of the invention andthe motor cooling system of the electric vehicle.

In the various figures of the drawings, the same numerals designate thesame or similar parts. Furthermore, when the term “first”, “second”,“third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar termsare used hereinafter, it should be understood that these terms referonly to the structure shown in the drawings as it would appear to aperson viewing the drawings, and are utilized only to facilitatedescribing the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2, a generator is disclosed according to a preferredembodiment of the invention. The generator 1 includes a liquid tank 11,a high temperature device 12 and a nozzle unit 13. The high temperaturedevice 12 and nozzle unit 13 are disposed in the liquid tank 11. Thenozzle unit 13 can spray liquid on the high temperature device 12.

The liquid tank 11 has a receiving room 111 and a backflow tube 112. Thebackflow tube 112 may be disposed on a bottom of the liquid tank 11 oron a surface of the liquid tank 11 adjacent to the bottom of the liquidtank 11. In addition, the backflow tube 112 has one end communicatingwith the receiving room 111 and the other end communicating with anabsorber 4 (see FIG. 3). A working fluid 5 circulates around thegenerator 1 and absorber 4 for circulating cooling purposes. The workingfluid 5 consists of a low-concentration working fluid 5 a and ahigh-concentration working fluid 5 b. A first circulation tube 113 maybe disposed on a top of the liquid tank 11 or on a surface of the liquidtank 11 adjacent to the top of the liquid tank 11. The first circulationtube 113 has one end communicating with the receiving room 111 and theother end communicating with a condenser 2.

The high temperature device 12 may be disposed on a surface of theliquid tank 11 adjacent to the top of the liquid tank 11. In thisembodiment, the high temperature device 12 may be further coupled with aconduction member 121, which can absorb the heat of the high temperaturedevice 12 and thus maintains at a high temperature. Both the conductionmember 121 and high temperature device 12 are disposed in the receivingroom 111.

The nozzle unit 13 includes a tank 131, an injecting tube 132, a nozzle133 and an oscillating device 134. The tank 131 is disposed in thereceiving room 111 of the liquid tank 11 and can receive thelow-concentration working fluid 5 a. The injecting tube 132 has one endcommunicating with the tank 131 and the other end communicating with theabsorber 4. The nozzle 133 can be disposed on a surface of the tank 131and faces the conduction member 121 of the high temperature device 12.The oscillating device 134 is disposed on the tank 131 and can induceoscillation of the low-concentration working fluid 5 a in the tank 131by way of high frequency oscillation, thus controlling the pressure ofthe low-concentration working fluid 5 a. Based on this, thelow-concentration working fluid 5 a in the tank 131 can periodicallyflow to the nozzle 133 and can be sprayed on the conduction member 121.

The oscillating device 134 may be a piezoelectric film that can beelectrified to cause oscillation, pushing the low-concentration workingfluid 5 a in the tank 131 to be sprayed out via the nozzle 133. Theoscillating device 134 has a plurality of operation modes that can beswitched by way of frequency control, enabling the nozzle 133 tointermittently spray the low-concentration working fluid 5 a on theconduction member 121. In this way, poor heat conduction of theconduction member 121 resulting from constant spraying of thelow-concentration working fluid 5 a may be avoided.

FIG. 3 shows an absorption refrigeration system including a generator 1,a condenser 2, an evaporator 3 and an absorber 4. The generator 1communicates with the condenser 2 via a first circulation tube 113. Thecondenser 2 communicates with the evaporator 3 via a second circulationtube 21. The evaporator 3 communicates with the absorber 4 via a thirdcirculation tube 31 having an expansion valve 32 disposed at a positionadjacent to the evaporator 3. The absorber 4 communicates with the tank131 of the generator 1 via the injecting tube 132 and communicates withthe liquid tank 11 of the generator 1 via the backflow tube 112. Thebackflow tube 112 may be partially disposed in the injecting tube 132without communication therewith, so that the backflow tube 112 can haveheat exchange with the liquid in the injecting tube 132.

The low-concentration working fluid 5 a that enters the tank 131 via theinjecting tube 132 may be sprayed into the receiving room 111 of theliquid tank 11 by the nozzle 133 based on oscillation of the oscillatingdevice 134, allowing the low-concentration working fluid 5 a to contactthe conduction member 121 of the high temperature device 12. Based onthis, a portion of the sprayed low-concentration working fluid 5 a willbe instantly steamed out and the other portion of the sprayedlow-concentration working fluid 5 a won't be steamed out. Therefrigerant in the portion of low-concentration working fluid 5 a thatis steamed out will become a gaseous refrigerant with high temperatureand high pressure. The high-temperature and high-pressure gaseousrefrigerant then flows from the generator 1 to the condenser 2 via thefirst circulation tube 113 and condenses into a liquid refrigerant withmiddle temperature. Meanwhile, the other portion of the sprayedlow-concentration working fluid 5 a that is not steamed will drip downand accumulate in the receiving room 111 of the liquid tank 11 to formthe high-concentration working fluid 5 b. The high-concentration workingfluid 5 b flows back to the absorber 4 via the backflow tube 112.

The middle-temperature liquid refrigerant in the condenser 2 enters theevaporator 3 via the second circulation tube 21 and has a temperaturedrop in the evaporator 3, thus forming a low-temperature liquidrefrigerant. The pressure of the low-temperature liquid refrigerant isreduced by the expansion valve 32 and the low-temperature liquidrefrigerant is sprayed into the third circulation tube 31 to produce agaseous refrigerant with low temperature and low pressure. Note theabsorber 4 is in a low pressure of vacuum or nearly vacuum. Therefore,the low-temperature and low-pressure gaseous refrigerant will beautomatically pulled into the absorber 4 via the third circulation tube31, absorbing the heat from the ambient environment for cooling effect.

The low-temperature and low-pressure gaseous refrigerant in the thirdcirculation tube 31 will mix with the working fluid 5 in the absorber 4that is at a room temperature, diluting the high-concentration workingfluid 5 b that flows back to the absorber 4. As a result, the workingfluid 5 will have lower concentration after dilution. The dilutedworking fluid 5 will reenter the tank 131 via the injecting tube 132 forreuse, allowing the low-concentration working fluid 5 a andhigh-concentration working fluid 5 b to constantly circulate around thegenerator 1 and absorber 4.

Based on the design that the backflow tube 112 is partially disposed inthe injecting tube 132 without communication therewith, thehigh-concentration working fluid 5 b that is at a high temperature isallowed to pass its heat to the injecting tube 132 while flowing back tothe absorber 4. Therefore, the low-concentration working fluid 5 a thatenters the tank 131 via the injecting tube 132 can be preheated tofacilitate vaporizing the low-concentration working fluid 5 a sprayed onthe high temperature device 12.

The generator of the invention improves the vaporization efficiency ofthe refrigerant of the working fluid 5 by directly spraying the workingfluid 5 on the high temperature device 12 in an impingement coolingmanner, so as to improve the circulation efficiency of the absorptionrefrigeration system. Since the vaporization efficiency of therefrigerant of the working fluid 5 is improved, lesser energy can beprovided to the high temperature device 12 for energy saving.

The generator of the invention can be applied to various equipmentsusing an absorption refrigeration system for cooling purposes. In suchan application, the high temperature device 12 can be heated up by theexhausted heat generated by other components of the equipments toachieve full utilization of energy. Following, an example showing theuse of the generator in an electric vehicle (in which the generator iscoupled with a refrigeration system of the electric vehicle, as well asa motor cooling system of the electric vehicle) is described.

FIG. 4 shows an exemplary use of the generator of the invention. Toefficiently collect the exhausted heat generated by a motor coolingsystem 6 of the electric vehicle, the motor cooling system 6 includes ahousing 61, a fan 62, a heat-storing medium 63 and a heat-conductingdevice 64. The housing 61 includes essential components of a motor suchas a stator or rotor. The fan 62 is coaxially mounted with the rotor andincludes a plurality of vanes protruding out of one end of the housing61. The heat-storing medium 63 is disposed on the other end of thehousing 61. The heat-storing medium 63 may be a porous material that canprovide a ventilation function while storing heat, such as aluminummaterial or ceramic. The heat-conducting device 64 is disposed on a faceof the heat-storing medium 63 that faces away from the housing 61. Theheat-conducting device 64 may be a metal material with excellent heatconductivity such as a copper.

When the fan 62 operates, external cool air is drawn into the housing 61and the heat generated by internal components of the housing 61 isguided to the heat-storing medium 63 for storing. Since the heat-storingmedium 63 is porous, a small portion of the heat can be expelled fromthe housing 61 therethrough, whereas most heat goes to theheat-conducting device 64, heating up the heat-conducting device 64. Inthis embodiment, the face of the heat-conducting device 64 that abutsagainst the heat-storing medium 63 may be a saw-toothed face to increasethe contact area between the heat-conducting device 64 and heat-storingmedium 63. Thus, heat absorption of the heat-conducting device 64 isfacilitated.

Referring to FIG. 5, the motor cooling system 6 may be connected to thegenerator 1 of the absorption refrigeration system, serving as a heatsource providing required heat for cyclic vaporization operation of thegenerator 1. In the embodiment, the heat-conducting device 64 of themotor cooling system 6 may be connected to the high temperature device12 of the generator 1, allowing the exhausted heat generated duringoperation of a motor using the motor cooling system 6 to be concentratedon the high temperature device 12. In this way, heat required foroperation of the generator 1 can be provided. Advantageously, noadditional energy of the electric vehicle is consumed, preserving moreenergy for other systems of the electric vehicle. Thus, overallperformance of the electric vehicle is improved. By coupling therefrigeration system and the motor cooling system 6 together, not onlythe overall volume of a power plant of the electric vehicle can bereduced to improve the space availability of the electric vehicle, butalso more energy can be saved to improve the motive power of theelectric vehicle. Moreover, when the refrigeration system operates, noextra burden is caused for a power source of the electric vehicle, thusnot affecting operation of other systems of the electric vehicle.

Furthermore, the refrigeration system may also be coupled to othersystems that generate/exhaust heat, such as a battery unit, powergenerator or current transformer. Thus, the exhausted heat of thesystems can be reused in an efficient manner. As can be readilyappreciated by one skilled in the art, the refrigeration system can alsobe coupled with other systems rather than just the motor cooling system.

Although the invention has been described in detail with reference toits presently preferable embodiment, it will be understood by one ofordinary skill in the art that various modifications can be made withoutdeparting from the spirit and the scope of the invention, as set forthin the appended claims.

1. A generator, comprising: a liquid tank having a receiving room; ahigh temperature device disposed on a surface of the liquid tank; and anozzle unit having a tank, an injecting tube, a nozzle and anoscillating device, wherein the tank is disposed in the receiving roomand is filled with a working fluid, the injecting tube has one endcommunicating with the tank, the nozzle is disposed on a surface of thetank and faces the high temperature device, the oscillating device isdisposed on the tank to induce oscillation of the working fluid in thetank, and the oscillation changes the pressure of the working fluid sothat the working fluid is pulled towards the nozzle and is sprayed onthe high temperature device by the nozzle.
 2. The generator as claimedin claim 1, wherein the high temperature device is coupled with aconduction member disposed in the receiving room of the liquid tank. 3.The generator as claimed in claim 1, wherein the oscillating device is apiezoelectric film.
 4. The generator as claimed in claim 1, wherein thehigh temperature device is coupled with a cooling system.
 5. Thegenerator as claimed in claim 4, wherein the cooling system includes aheat-conducting device coupled with the high temperature device.
 6. Thegenerator as claimed in claim 5, wherein the heat-conducting device hasone face abutting against a heat-storing medium made of a porousmaterial.
 7. The generator as claimed in claim 6, wherein the face ofthe heat-conducting device that abuts against the heat-storing medium isa saw-toothed face to increase the contact area between theheat-conducting device and the heat-storing medium.